Light flux controlling member, light emitting device, surface light source device, display device, and method for improving luminance unevenness of light emitting device

A light flux controlling member includes n incidence units for allowing incidence of light emitted from n light emitting elements, respectively; an emission unit disposed between the n incidence units and allowing emission of the light incident on the n incidence units while guiding the light; and a plurality of legs. Each incidence unit includes an incidence surface and a reflection surface reflecting, in a direction along the substrate, the light incident on the incidence surface. The emission unit includes a first emission surface emitting a part of the light from the incidence unit, and a second emission surface disposed so as to face away from the first emission surface and emitting another part of the light from the incidence unit. Each leg is disposed at a position satisfying a predetermined condition.